BU-414: Charger Chips


Charger design has been simplified through chips that embed charge intelligence. When first introduced in the 1980s, these chips were hot commodities and were made popular with the arrival of NiMH and Li-ion that need special charging algorithms. Charger chips have since matured and serve in more basic charging devices.

Although charger chips are easy to use, they have limitations. Most offer a fixed charge algorithm that does not permit fine-tuning for specialty uses. Features such as “boost,” which reactivates the protection circuit when a Li‑ion battery falls asleep, do not exist, nor can a charger chip accommodate different chemistries selectable by a code, or do ultra-fast charging with safeguards that include scaling the charge current to battery condition and temperature. Temperature control is mostly through an on/off switch.

Microcontrollers offer an alternative to charger chips. Although the design cost is higher because of programming, manufacturing costs are compatible to charger chips. We must keep in mind that the charge chip or microcontroller form only a small part of the charger circuit, and the bulk of the cost lies in the peripheral components, which include solid-state switches and the power supply. The cost of these parts is in direct relationship to current handling.


On February 20, 2012 at 8:31am
Asadullah wrote:

plz tell me how much resistance is required to converts volts from high voltage to low voltage.

On February 20, 2012 at 11:12am
ResistorGuru wrote:

The answer is 2GHz.

But you might want to check out this site if you want to verify the answer: http://en.wikipedia.org/wiki/Voltage_divider…

On January 28, 2014 at 8:25am
mathavan wrote:

how to create charger with help of flyback converter without current feedback

On February 6, 2014 at 4:11pm
Alexis Pomares wrote:

Very good site. Could you comment something about some charger chips references? I mean in your so good style (referring to chemistry type, including advantages, limitations, etc).

On June 4, 2014 at 6:18am
George Mountcastle wrote:

I am making a device where I am using LI-ion batteries in a 6v pack and a 12v pack.  The 6v pack consists of 2 batteries in series and 5 of these sets in parallel. The 12 volt pack is 4 batteries in series with two sets in parallel.  The battery type is a CR123.  Does anyone make a charger or do i need to make my own?\

Please verify what I have read to be correct the max V is 4.2v/cell and current to be 1 amp.

On August 17, 2014 at 4:42am
Dave wrote:

I am making a charger which can charge 3 cell of Ni-MH cell in series and single cell Li-Ion battery, the charge algorithms should be different. Could you help how to determinate the battery type?